Airbags save thousands of lives each year in the States and here in Canada. But even after more than 2 decades after they've become mandatory in most cars, the auto industry still struggles to master the complex systems that must work flawlessly in less than a second. The recent recall of Takata air bags and General Motor's recall of their ignition switches highlights the problems that can occur when airbags actually deploy and when they don't.
|A rundown of what actually occurs when airbags expand|
Takata airbags, found in many new cars on the market today, have been recently recalled after new evidence came to light about the dangers they pose to drivers and passengers. Over 100 injuries and 5 deaths have been due to the airbags, who send metal shrapnel flying when deployed. Despite extensive research, a single cause has not been identified. Some suspect the ammonium nitrate itself, only recently used in their airbags, and hailed as a "new technological edge" by a company engineer (Paresh Khandhadia, 2009).
According to experts, ammonium nitrate breaks down over time and is very sensitive to temperature changes and moisture. Under these conditions, they say, it can combust violently (Hiroko Tabuchi, 2014). Interestingly, it becomes unstable at about 100 degrees. The inside of a car in summer may get as warm as 140 degrees! But it's cheap. Unbelievably so. Some say the switch from sodium azide (as seen in the inflation device diagram) to ammonium nitrate in 1998 was not for cost reasons, but for the environment. Ammonium nitrate produced gas much more efficiently with fewer emissions in their trials, says Alby Berman, a spokesperson for the brand. Either way, the company continues to use ammonium nitrate in their replacement air bags.
Another theorized issue is the quantity of ammonium nitrate involved in the equation. The New York Times published a video in 2014 depicting scenes of dropped air bag 'kits' and other mishaps on the assembly line. Sources who wished to remain anonymous told the newspaper that there was such enormous pressure to keep with demand, that sending potentially defective or damaged product back was not popular with management. If the amount of ammonium nitrate varied even a little from bag to bag, this could severely impact the resulting chemical reaction. As studied in stoichiometry, a change in the amount of reactants can completely alter the reaction itself. These unknown changes are not something you want coming at your face or your family's faces at 200 mph.
In my opinion, Takata is playing with fire. Using ammonium nitrate may be cheaper and 'produce less emissions', but at what cost? It seems almost crass to continue using the compound when it may or may not be involved in many deaths and injuries. Personally, I'm grateful neither of my parents cars use Takata airbags. Even though we've never been in an accident, it's still much better to know we won't have shrapnel coming at us inside our own car. I hope as much effort as possible is put into researching the cause of these malfunctions and correcting it. At the very least, ensuring quality product off the assembly line is a good first step.
My questions to you:
1. Do the benefits of ammonium nitrate outweigh the costs, in your opinion? After all, they don't ALL explode.
2. Should Takata have recalled only the airbags from cars registered in more humid/warm cities? Why or why not?
3. Compare sodium azide to ammonium nitrate. Why is sodium azide purportedly safer?
4. If you could give a piece of advice to the CEO of Takata, what would it be?